Hardwood flooring generally consists of a number of juxtaposed elongated tongue-and-groove planks interlocked with each other, and then fastened in position to a subjacent subfloor. To fasten these hardwood planks to the subfloor of a room (composed for example of plywood plates and/or floor joists), it is known to use a dedicated pneumatic nailer. A pneumatic nailer for hardwood flooring generally comprises a main body carrying a floor-engageable shoe mounted to its bottom surface, upon which the nailer rests against a hardwood plank prior to discharging a fastener in the latter.
The pneumatic nailer also comprises an actuator housing on the nailer's main body and connected to a pressurized air source (e.g. an air compressor). The actuator housing has a casing defining a pressurized air chamber therein, the casing carrying a fastener discharge mechanism comprising an actuator head and a piston assembly. The piston assembly comprises a cylinder defining a cylinder chamber, and a plunger mounted inside the cylinder chamber and movable therein between upper and lower limit positions. The plunger in turn comprises a head portion engaging the inner peripheral wall of the cylinder in airtight fashion, and a striking rod carried by the plunger head.
Moreover, a magazine is mounted to the nailer and serially feeds fasteners, in the form of metallic L- or T-shaped barbed cleats or staples, into a fastener ejection channel defined by the actuator housing.
At rest, a valve of the actuator head is positioned in a closed position, in which it cuts off fluid communication between the upper portion of the piston's cylinder chamber (the portion located above the plunger head) and the pressurized air chamber. To set off a fastener discharge cycle of the nailer, a workman activates a trigger thereof, which causes the valve to shift to its open position and to enable air to be admitted in the piston's cylinder above of the plunger head, which causes the plunger to move with great force and celerity from its upper limit position to its bottom limit position. As the plunger travels from its upper to its bottom limit position, the striking rod thereof sweeps the fastener ejection channel containing a fastener. The fastener is consequently forced out of the nailer and driven into the subjacent workpiece.
On certain nailers, the fastener discharge cycle is set off by striking an impact-receiving actuator head with a mallet; on other types of nailers, the fastener discharge cycle is set off when the user pushes a switch on the pneumatic nailer.
Such nailers are designed to have an extended longevity, and the internal components of the actuator housing of such nailers need to be maintained at regular intervals during their extended lifetime in order to remain in functioning condition. More particularly, the fastener discharge mechanism—composed of an intricate arrangement of movable parts—needs to be regularly accessed in order to be cleaned, lubricated, repaired or generally maintained.
In prior art devices, performing maintenance tasks on the fastener discharge mechanism can be tedious, and even problematic if the appropriate tools are not handy, as some of the parts of the fastener discharge mechanism cannot be accessed without disassembling and opening up the casing.